CVE-2017-18236 in Exempi
Summary
by MITRE
An issue was discovered in Exempi before 2.4.4. The ASF_Support::ReadHeaderObject function in XMPFiles/source/FormatSupport/ASF_Support.cpp allows remote attackers to cause a denial of service (infinite loop) via a crafted .asf file.
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Analysis
by VulDB Data Team • 02/22/2023
The vulnerability identified as CVE-2017-18236 represents a critical denial of service weakness within the Exempi library version 2.4.3 and earlier. This flaw exists in the ASF_Support::ReadHeaderObject function located in XMPFiles/source/FormatSupport/ASF_Support.cpp, which is part of Adobe's XMP SDK implementation. The issue specifically affects applications that process ASF (Advanced Systems Format) media files, creating a potential vector for remote attackers to disrupt system operations through carefully crafted malicious files.
The technical flaw manifests as an infinite loop condition that occurs when processing malformed ASF files. Attackers can exploit this by creating specially constructed .asf files that trigger the vulnerable code path in the ASF_Support::ReadHeaderObject function. When the library attempts to parse these crafted files, the parsing logic enters an endless loop, consuming system resources and effectively causing a denial of service condition. This behavior aligns with CWE-835, which classifies infinite loops as a weakness that can lead to resource exhaustion and system unavailability.
The operational impact of this vulnerability extends beyond simple service disruption as it affects any application or system that relies on Exempi for processing ASF media files. This includes content management systems, media processing pipelines, digital asset management platforms, and various multimedia applications that utilize Adobe's XMP toolkit. The vulnerability is particularly concerning because it can be exploited remotely without requiring authentication, making it an attractive target for attackers seeking to disrupt services. Systems processing untrusted ASF content are at risk, potentially leading to cascading failures in media processing workflows and service availability issues.
Mitigation strategies for CVE-2017-18236 primarily focus on upgrading to Exempi version 2.4.4 or later, which contains the necessary patches to address the infinite loop condition. Organizations should prioritize patching affected systems and applications that utilize the Exempi library, particularly those handling user-uploaded or externally sourced ASF files. Additionally, implementing proper input validation and sanitization measures can provide defense-in-depth protection, though the primary fix remains the software update. Security monitoring should include detection of unusual resource consumption patterns that might indicate exploitation attempts, and network segmentation can help limit the potential impact of successful attacks. This vulnerability demonstrates the importance of proper input validation and the potential for seemingly benign parsing logic to create severe operational disruptions, aligning with ATT&CK technique T1499.004 for resource exhaustion attacks.